A waterproof case for automobile components includes: a case body part that includes a storage space for housing an object and an opening connecting to the storage space; and a lid part that is configured to be attached to the case body part to close the opening. A seal material (made of an adhesive silicone gel is interposed between the case body part and the lid part. An acceptance part is provided in at least one of the case body part and the lid part. An engagement convex part is configured to be locked in the acceptance part at a position corresponding to the acceptance part in the case body part and the lid part.