An optical disk device has: a detector (11) that converts a reflected light from an optical disk (5) and a reflected light of an incident light from a light source (1) side of a solid immersion lens (4), into electric signals and outputs the signals; a subtracter (15) that computes the output signal of the detector (11) according to a predetermined rule and outputs the result as a tilt detection signal; a CPU (21), an amplifier/phase compensation circuit (16), a switch (17) and an actuator (13) that perform tilt control for controlling tilt of the solid immersion lens (4) with respect to the optical disk (5) using the tilt detection signal; and the CPU (21), a nut (24), a feed screw (25), a decelerator (26) and a stepping motor (27) that perform gap adjustment for changing the gap of the solid immersion lens (4) and optical disk (5), and in the process of adjustment of gap between the solid immersion lens (4) and optical disk (5), the CPU (21) enables tilt control by closing the switch (17) according to the tilt detection signal.