A power transmitting device performs power transmission to a power receiving device. The power receiving device is provided in a space that a person can enter or exit. The power transmitting device includes a power transmitting unit, a processing circuitry, and a reception unit. The power transmitting unit is configured to perform power transmission to the power receiving device through contactless power supply. The processing circuitry is configured to switch a power transmission mode of the power transmitting unit between a normal-output mode and a limit mode in which a transmitted power is more limited than in the normal-output mode. The reception unit is configured to receive a limit instruction for the power transmission given by the person. The processing circuitry is configured to set the power transmission mode to the limit mode when the reception unit receives the limit instruction.