A semiconductor apparatus includes an arithmetic circuit that executes a program based on an operating clock signal input through a clock transfer node, an internal oscillator that generates an internal clock signal to be used internally, a watch dog timer that counts the internal clock signal, detect that a count value reaches a predetermined value of an execution time of the program in the arithmetic circuit and output a notification signal, and a clock monitor circuit that detects presence or absence of the operating clock signal in response to the notification signal.