A coil apparatus that can increase mechanical strength of terminal portions and assure sufficient impact resistant properties and vibration resistant properties even in an application in a severe use environment such as an in-vehicle coil apparatus. Terminals are formed of one metal sheet, and include an attachment portion, an intermediate portion, and a bottom portion. One end of the attachment portion is fixed at each terminal attachment portion of a core. One end of the intermediate portion is continuous with the other end of the attachment portion at a first bent portion. The bottom portion has a first end continuous with the other end of the intermediate portion at a second bent portion, facing the attachment portion, and a second free end. The intermediate portion has a hole in a plane thereof. In each hole, both inner edges that are opposed to each other in at least one direction have an arc shape.