According to one embodiment, a drive circuit includes a first circuit part. The first circuit part includes a first detecting part, a second detecting part, a first circuit, and a second circuit. The first detecting part is configured to detect a first piezoelectric element current flowing in a first piezoelectric element, and output a first detection signal corresponding to the first piezoelectric element current. The second detecting part is configured to detect a first capacitance element current flowing in a first capacitance element, and output a second detection signal corresponding to the first capacitance element current. The first circuit includes a first input terminal and a second input terminal. The first circuit is configured to apply a first drive signal to the first piezoelectric element and the first capacitance element. The second circuit is configured to supply a first differential signal to the second input terminal.