PROBLEM TO BE SOLVED: To provide an oil filling plug that can prevent leakage of oil and intrusion of rain water.SOLUTION: An oil filling plug 31 blocks an oil filling hole 30 of case 4, 8 that is an oil storage body of an agricultural machine 1. The oil filling plug 31 includes a plug body 34 with an air discharge hole for discharging internal air from the case 4, 8. An elastic body 35 for opening and closing the air discharge hole is provided in a groove part in an upper side outer peripheral part of the plug body 34 so as to be detachable.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】油の漏出や雨水の浸入を防止できる注油栓を提供する。【解決手段】注油栓31は、農作業機1の油収容体であるケース4,8の注油孔30を塞ぐものである。注油栓31は、ケース4,8内の空気を排出するための空気排出孔を有する栓本体34を備える。栓本体34の上側外周部の溝部には、空気排出孔を開閉する弾性体35を脱着可能に設ける。【選択図】図1