A noncontact transmission device 100 is provided with a driver 106 for driving a coil 102; a system clock oscillator 110 for outputting a system clock; a monitoring clock oscillator 112 for outputting a monitoring clock LF0 having a frequency lower than that of the system clock CK0; and a control circuit 108. The control circuit 108 outputs a system clock oscillating control signal S60 based on the monitoring clock LF0 while being in a standby state and makes the system clock oscillator 110 intermittently output a system clock CK0 in synchronization with the control signal S60. In a period when the system clock CK0 is being outputted, the coil 102 is driven by a driver control signal SD and whether the device 200 to which data is to be transmitted is arranged or not is detected.