To reduce an error in delay adjustment.

In data transmission, a control signal is continuously transmitted at a predetermined period, and at timings when a data signal to be transmitted is present, the data signal is transmitted in succession to the control signal. In a distortion compensation device for distortion-compensating the transmission signal, trigger signal generation means 2 generates a trigger signal according to the control signal, timing difference adjustment means 3 adjusts a timing difference of the transmission signal between a signal yet to be distortion-compensated and a distortion-compensated feedback signal at an operation timing based on the trigger signal, distortion compensation mode generation means 4 generates a mode of distortion compensation in accordance with an error between the adjusted signal yet to be distortion-compensated and the distortion-compensated feedback signal, and distortion compensation execution means 1 applies distortion compensation to the transmission signal according to the mode of distortion compensation.