An image supplying method includes the steps of: transmitting encoded video data including a key frame that is encoded by an inter-frame encoding process; receiving a seek operation and acquires a first play point in a desired seek position of the encoded video data; determining a search range including the acquired first play point; searching for key frames from the determined search range; determining a position of a key frame having a shortest distance from the first play point as a second play point in a case where the key frame is detected from the search range by the key frame searching unit; and transmitting the encoded video data from the key frame corresponding to the determined second play point.