A motor controller includes an H-bridge circuit, a switching-element driving circuit, a motor-current detection circuit, a sample hold circuit executing a sample hold of an output of the motor-current detection circuit at every half period and outputting the output of the motor-current detection circuit as a first signal and a second signal, according to a PWM output timing of the switching-element driving circuit, and a motor-current calculation circuit selecting a signal that is larger between the first signal and the second signal as a selection signal, calculating a value of the selection signal as an absolute value of a motor current, determining a current direction based on a relation between the selection signal and a PWM output signal at a sample timing that the selection signal is obtained.