A power transmission-side apparatus comprising: a resonance type transmission power supply device for converting input power into high-frequency power and outputting the high-frequency power; and a power transmitting coil for transmitting the high-frequency power outputted from the resonance type transmission power supply device, wherein the resonance type transmission power supply device includes: an inductor in which one end thereof is connected to one of a pair of input terminals; a switching element that is a field effect transistor for performing switching operation at a high frequency on the basis of a drive signal, the field effect transistor being connected between the other end of the inductor and the other of the input terminals; a resonant circuit (C2, C3, L2) that is disposed between the switching element and the power transmitting coil, and makes the switching operation of the switching element to be resonant switching operation; a switching parameter detecting unit for detecting a switching voltage of the switching element; an abnormality detecting unit (264a to 264e, 265) for comparing the switching voltage detected by the switching parameter detecting unit with a threshold value for determining whether the switching voltage is within a normal range, and outputting an abnormal signal indicating an abnormality caused by foreign matter when the switching voltage detected by the switching parameter detecting unit is not within the normal range; a shutdown circuit for outputting a signal instructing a forced stop when the abnormal signal is received from the abnormality detecting unit; a PWM on/off control circuit for outputting a PWM signal, and for stopping an output of the PWM signal when the signal instructing the forced stop is received from the abnormality detecting unit; and a drive circuit for outputting the drive signal to the switching element on the basis of the PWM signal from the PWM on/off control circuit. a resonance type transmission power supply device for converting input power into high-frequency power and outputting the high-frequency power; and a power transmitting coil for transmitting the high-frequency power outputted from the resonance type transmission power supply device, wherein the resonance type transmission power supply device includes: an inductor in which one end thereof is connected to one of a pair of input terminals; a switching element that is a field effect transistor for performing switching operation at a high frequency on the basis of a drive signal, the field effect transistor being connected between the other end of the inductor and the other of the input terminals; a resonant circuit (C2, C3, L2) that is disposed between the switching element and the power transmitting coil, and makes the switching operation of the switching element to be resonant switching operation; a switching parameter detecting unit for detecting a switching voltage of the switching element; an abnormality detecting unit (264a to 264e, 265) for comparing the switching voltage detected by the switching parameter detecting unit with a threshold value for determining whether the switching voltage is within a normal range, and outputting an abnormal signal indicating an abnormality caused by foreign matter when the switching voltage detected by the switching parameter detecting unit is not within the normal range; a shutdown circuit for outputting a signal instructing a forced stop when the abnormal signal is received from the abnormality detecting unit; a PWM on/off control circuit for outputting a PWM signal, and for stopping an output of the PWM signal when the signal instructing the forced stop is received from the abnormality detecting unit; and a drive circuit for outputting the drive signal to the switching element on the basis of the PWM signal from the PWM on/off control circuit. an inductor in which one end thereof is connected to one of a pair of input terminals; a switching element that is a field effect transistor for performing switching operation at a high frequency on the basis of a drive signal, the field effect transistor being connected between the other end of the inductor and the other of the input terminals; a resonant circuit (C2, C3, L2) that is disposed between the switching element and the power transmitting coil, and makes the switching operation of the switching element to be resonant switching operation; a switching parameter detecting unit for detecting a switching voltage of the switching element; an abnormality detecting unit (264a to 264e, 265) for comparing the switching voltage detected by the switching parameter detecting unit with a threshold value for determining whether the switching voltage is within a normal range, and outputting an abnormal signal indicating an abnormality caused by foreign matter when the switching voltage detected by the switching parameter detecting unit is not within the normal range; a shutdown circuit for outputting a signal instructing a forced stop when the abnormal signal is received from the abnormality detecting unit; a PWM on/off control circuit for outputting a PWM signal, and for stopping an output of the PWM signal when the signal instructing the forced stop is received from the abnormality detecting unit; and a drive circuit for outputting the drive signal to the switching element on the basis of the PWM signal from the PWM on/off control circuit.