Abstract: Disclosed herein is an attachment-type auxiliary device using a magnet. The attachment-type auxiliary device is used in conjunction with a product having a built-in magnetic substance. The attachment-type auxiliary device includes: a detachable part including a detachable body, and a magnet configured to be magnetically coupled with the magnetic substance; an accessory part coupled to the rear side of the detachable body, and configured to form an accommodation space and to support the product so that the product is placed in a tilted state; and a coating part made of a material having slip resistance, and formed on the front surface of the detachable body.