The present invention relates to an oiling apparatus which quantitatively applies grease or the like on a crane rail. The oiling apparatus comprises: a body (20) having an applying part (21) and an oil supply part (22), and movable on rails facing each other; an applying means (30) having an applying wheel (33) and a guide roller (35) on the body, and maintaining contact of the applying wheel (33) with the rails; an oil supply means (40) having an oil supply container (41) and an oil supply pump (45) on the body (20), and transporting grease to the applying wheel (33); a generating means (50) installed to generate independent electricity to the body (20); and a control panel (60) installed to apply the electricity of the generating means (50) to the applying means (30) and the oil supply means (40). Accordingly, the present invention induces quantitative supply of grease based on a self-generating method which excludes separate connection or wiring in a process of applying grease on large crane rails of various industrial sites to increase speed and accuracy.COPYRIGHT KIPO 2021