There is disclosed a stream data reception/reproduction device capable of suppressing deterioration of quality of stream data reproduced even when the stream data is received via an IP network or the like in which the packet arrival timing and the order are not guaranteed. In this device, a reproduction speed control unit (107) sets various conditions in accordance with the value of the synchronization difference reported from a synchronization difference calculation unit (102). Only when the set conditions are satisfied, the speed of reproduction of a frame decompressed and inputted from a decoding unit (105) is adjusted. The reproduction speed control unit (107) interpolates a predetermined amount of sample data into the frame or decimates it from the frame when adjusting the reproduction speed.