In a brushless motor apparatus, a brushless motor has a rotor and Y-connected coils, and a controller has an inverter circuit selectively driving the coils. The controller detects an induced voltage generated in a specific coil which is not driven by the inverter circuit while the rotor rotates. The controller acquires a positional signal of the rotor on a basis of a timing at which the induced voltage reaches the reference value. The timing is obtained through comparison between the detected induced voltage and a reference value. The controller switches a coil driven by the inverter circuit on a basis of the positional signal, and sets a mask period on a basis of a result of comparison between voltage of the specific coil and a coil other than the specific coil. The comparison between the induced voltage and the reference value is not executed in the mask period.