This invention relates to an illuminator, particularly to an LED illuminator. The LED illuminator disclosed in an embodiment of the invention comprises: a body unit which forms a body of the illuminator and wherein a side of a central portion is open; an LED module unit which is attached to and detached from a body unit in correspondence to the shape of the body unit and includes an LED emitting light; and an optical sheet which is placed at a front side of the LED and irradiates the light emitted from the LED toward the open side of the body unit. According to the invention, various LED modules can be attached to and detached from the illuminator at a low cost.
