A command transmission/reception section (4R), a power-control determination section (8) and a power control section (9) are provided in a controlled device (3) which is connected to a network (1) and which performs power control in response to a command transmitted from a control device (2). Upon receipt of a power control command from the control device (2), the power-control determination section (8) determines as to power-on/power-off in units of a block, and performs power control on the basis of a result of the determination. Consequently, unnecessary power-on in, for example, video reservation can be prevented.