To provide a user with an image transmission system, an image storage device, and a program capable of uploading image data with simple operation.

An image transmission system 1 comprises a digital camera 10, a PC 40, and a Web server 50. The digital camera 10 stores a plurality of pieces of image data, printing request information, and transmission request information. The digital camera 10 determines whether a connection destination is a printing device or an external apparatus differing from the printing device when detecting external connection, transmits image data with which the printing request information is associated to the printing device, when it is determined that the connection destination is the printing device, and transmits image data with which the transmission request information is associated to the external apparatus, when it is determined that the connection destination is the external apparatus. The PC 40 receives the transmitted image data, and transmits the received image data to the Web server 50 through a communication network channel 51.