To make slope frame form work easy by spraying protection mortar in the form of a ridge after an adhesive agent is applied on the upper face sticking a carbon fiber sheet.

Slope frame positions (a), (b), (c), (d) which are intended to be constructed at intervals of height and width of approximately 1-4m are indexed on a mountain slope 1. Mortar 2 at width intervals of 10-80cm is placed not exceeding approximately 8cm on the indexed positions (a), (b), (c), (d), lever finish is flatly performed on the surface, and after an adhesive agent 4 is applied on the surface after drying, a carbon fiber sheet 4 is stuck on the surface with the adhesive agent 3. Furthermore, after the adhesive agent 3 is applied on the upper face of the sheet 4, protection mortar 5 is sprayed and formed in the form of a ridge protruded up to constant height, and an anchor 6 of 50cm-15m is driven at the intersection part of each ridge. Thus, reduction of labor and cost reduction can be contrived.