the objective of the present invention is to provide a coil unit for a primary coil with which the balance between the mechanical function and the electrical function can easily be adjusted . this coil unit is provided with : a bottom plate that makes contact with a road surface ; a shock absorber arranged on the upper surface of the bottom plate ; a frame accommodated within the shock absorber ; a shielding case that accommodates a primary coil and the upper part of which is accommodated within and opens into the frame ; a cover that covers the shielding case ; and supporting posts that abut against the shielding case and the cover , and support the cover . the bottom plate , the frame , and the cover , which are primarily responsible for mechanical performance , and the shielding case , which is responsible for electrical property , are formed as separate pieces .