Abstract: A retaining mechanism for retaining a surface coil of an MRI apparatus comprises a retaining unit for retaining the surface coil, supporting members each having a distal end connected to the retaining unit to support the same, and a mounting unit connected with the respective proximal ends of the supporting members so that the supporting members are mounted on a bed. Each supporting member is flexible enough to be bent by external force and retentive enough to maintain a bent posture. Thus, by bending the supporting members, the surface coil can be moved to and kept in a desired position. In this arrangement, the surface coil can be quickly moved onto a desired photographing region, and kept accurately on the predetermined region during photographing operation.