A satellite radio-controlled wristwatch, comprising: a satellite radio wave reception unit comprising an antenna for receiving a satellite radio wave, a high frequency circuit, and a decoder circuit; a clock circuit for holding and counting an internal time; and a controller for controlling timings of at least: an activation operation of supplying power to the satellite radio wave reception unit for activation thereof; an acquisition and tracking operation of acquiring and tracking a certain satellite radio wave by the satellite radio wave reception unit; and a time information acquisition operation of acquiring time information from the satellite radio wave received by the satellite radio wave reception unit, the controller being configured to: wait for an arrival of an activation time point, which is inversely calculated by subtracting an acquisition and tracking time period and an activation time period from a time information receivable time point that is predicted based on the internal time, and then start the activation operation; characterized in that the controller is further configured to vary the acquisition and tracking time period depending on a predetermined condition, and wherein the controller selects one of a plurality of predetermined time periods as the acquisition and tracking time period depending on the predetermined condition, wherein the controller selects, as the acquisition and tracking time period, any one of a first acquisition and tracking time period and a second acquisition and tracking time period longer than the first acquisition and tracking time period and, wherein the controller selects the first acquisition and tracking time period when a user selects manual reception, a position of a hand is not overlapped with the antenna in a plan view, a power supply voltage is equal to or more than a predetermined threshold voltage, and reception has succeeded in each of a predetermined previous number of times. a satellite radio wave reception unit comprising an antenna for receiving a satellite radio wave, a high frequency circuit, and a decoder circuit; a clock circuit for holding and counting an internal time; and a controller for controlling timings of at least: an activation operation of supplying power to the satellite radio wave reception unit for activation thereof; an acquisition and tracking operation of acquiring and tracking a certain satellite radio wave by the satellite radio wave reception unit; and a time information acquisition operation of acquiring time information from the satellite radio wave received by the satellite radio wave reception unit, an activation operation of supplying power to the satellite radio wave reception unit for activation thereof; an acquisition and tracking operation of acquiring and tracking a certain satellite radio wave by the satellite radio wave reception unit; and a time information acquisition operation of acquiring time information from the satellite radio wave received by the satellite radio wave reception unit, the controller being configured to: wait for an arrival of an activation time point, which is inversely calculated by subtracting an acquisition and tracking time period and an activation time period from a time information receivable time point that is predicted based on the internal time, and then start the activation operation; characterized in that the controller is further configured to vary the acquisition and tracking time period depending on a predetermined condition, and wherein wait for an arrival of an activation time point, which is inversely calculated by subtracting an acquisition and tracking time period and an activation time period from a time information receivable time point that is predicted based on the internal time, and then start the activation operation; characterized in that the controller is further configured to vary the acquisition and tracking time period depending on a predetermined condition, and wherein the controller selects one of a plurality of predetermined time periods as the acquisition and tracking time period depending on the predetermined condition, wherein the controller selects, as the acquisition and tracking time period, any one of a first acquisition and tracking time period and a second acquisition and tracking time period longer than the first acquisition and tracking time period and, wherein the controller selects the first acquisition and tracking time period when a user selects manual reception, a position of a hand is not overlapped with the antenna in a plan view, a power supply voltage is equal to or more than a predetermined threshold voltage, and reception has succeeded in each of a predetermined previous number of times.