diff --git a/app/services/line/incoming_message_service.rb b/app/services/line/incoming_message_service.rb
index 4761292d0..0d2f78c7a 100644
--- a/app/services/line/incoming_message_service.rb
+++ b/app/services/line/incoming_message_service.rb
@@ -76,7 +76,8 @@ class Line::IncomingMessageService
 
     response = inbox.channel.client.get_message_content(message['id'])
 
-    file_name = "media-#{message['id']}.#{response.content_type.split('/')[1]}"
+    extension = get_file_extension(response)
+    file_name = message['fileName'] || "media-#{message['id']}.#{extension}"
     temp_file = Tempfile.new(file_name)
     temp_file.binmode
     temp_file << response.body
@@ -93,12 +94,25 @@ class Line::IncomingMessageService
     )
   end
 
+  def get_file_extension(response)
+    if response.content_type&.include?('/')
+      response.content_type.split('/')[1]
+    else
+      'bin'
+    end
+  end
+
   def event_type_message?(event)
     event['type'] == 'message' || event['type'] == 'sticker'
   end
 
   def message_type_non_text?(type)
-    [Line::Bot::Event::MessageType::Video, Line::Bot::Event::MessageType::Audio, Line::Bot::Event::MessageType::Image].include?(type)
+    [
+      Line::Bot::Event::MessageType::Video,
+      Line::Bot::Event::MessageType::Audio,
+      Line::Bot::Event::MessageType::Image,
+      Line::Bot::Event::MessageType::File
+    ].include?(type)
   end
 
   def account
diff --git a/spec/services/line/incoming_message_service_spec.rb b/spec/services/line/incoming_message_service_spec.rb
index 3bcdf8b04..9160efff2 100644
--- a/spec/services/line/incoming_message_service_spec.rb
+++ b/spec/services/line/incoming_message_service_spec.rb
@@ -105,6 +105,40 @@ describe Line::IncomingMessageService do
     }.with_indifferent_access
   end
 
+  let(:file_params) do
+    {
+      'destination': '2342234234',
+      'events': [
+        {
+          'replyToken': '0f3779fba3b349968c5d07db31eab56f',
+          'type': 'message',
+          'mode': 'active',
+          'timestamp': 1_462_629_479_859,
+          'source': {
+            'type': 'user',
+            'userId': 'U4af4980629'
+          },
+          'message': {
+            'type': 'file',
+            'id': '354718',
+            'fileName': 'contacts.csv',
+            'fileSize': 2978
+          }
+        },
+        {
+          'replyToken': '8cf9239d56244f4197887e939187e19e',
+          'type': 'follow',
+          'mode': 'active',
+          'timestamp': 1_462_629_479_859,
+          'source': {
+            'type': 'user',
+            'userId': 'U4af4980629'
+          }
+        }
+      ]
+    }.with_indifferent_access
+  end
+
   let(:sticker_params) do
     {
       'destination': '2342234234',
@@ -241,5 +275,35 @@ describe Line::IncomingMessageService do
         expect(line_channel.inbox.messages.first.attachments.first.file.blob.filename.to_s).to eq('media-354718.mp4')
       end
     end
+
+    context 'when valid file message params' do
+      it 'creates appropriate conversations, message and contacts' do
+        line_bot = double
+        line_user_profile = double
+        allow(Line::Bot::Client).to receive(:new).and_return(line_bot)
+        allow(line_bot).to receive(:get_profile).and_return(line_user_profile)
+        file = fixture_file_upload(Rails.root.join('spec/assets/contacts.csv'), 'text/csv')
+        allow(line_bot).to receive(:get_message_content).and_return(
+          OpenStruct.new({
+                           body: Base64.encode64(file.read),
+                           content_type: 'text/csv'
+                         })
+        )
+        allow(line_user_profile).to receive(:body).and_return(
+          {
+            'displayName': 'LINE Test',
+            'userId': 'U4af4980629',
+            'pictureUrl': 'https://test.com'
+          }.to_json
+        )
+        described_class.new(inbox: line_channel.inbox, params: file_params).perform
+        expect(line_channel.inbox.conversations).not_to eq(0)
+        expect(Contact.all.first.name).to eq('LINE Test')
+        expect(Contact.all.first.additional_attributes['social_line_user_id']).to eq('U4af4980629')
+        expect(line_channel.inbox.messages.first.content).to be_nil
+        expect(line_channel.inbox.messages.first.attachments.first.file_type).to eq('file')
+        expect(line_channel.inbox.messages.first.attachments.first.file.blob.filename.to_s).to eq('contacts.csv')
+      end
+    end
   end
 end