To provide a device for adjusting the head gap of an ink-jet printer which can smoothly adjust the head gap between a head assembly and a printing medium.

The head gap is adjusted by rotating and vertically moving a shaft which has a support shaft fitted eccentriacally to both ends and to which the head assembly is fitted by a motor. A rotational angle regulation unit for restricting the rotational angle of a worm wheel which is connected to the support shaft and rotated, so as to limit the variation range of the head gap and a clutch unit for selectively transmitting the power of the motor to the worm wheel are provided so that an overload on the motor is prevented, and the head gap can be smoothly adjusted.