Abstract: An instrument converts to a security mode that disallows normal operations at the same time as it converts to a power saving mode that achieves a reduction in power consumption and the like when a preset power saving mode transition time has elapsed. In this security mode, background processing relating to each function is executed and, if some type of input is received, security mode termination processing is started, a password input screen is displayed, and the instrument enters a password input standby state. If the password input standby state is left on, and a preset security mode re-transition time that is shorter than the power saving mode transition time lapses, the instrument is restored to the security mode and power saving mode that existed prior to the start of the termination processing.