The development and design of the divertor plate in JAERI are presented. Small divertor models are fabricated and tested in an electron beam heating facility in the JAERI. Typical heat load is 10 MW/m2. The divertor models consist of CFC or isotropic graphite/Cu bonded structures. A twisted tape is inserted to enhance heat transfer. It is shown after 1000 thermal cycle tests that CFC-Cu bonded structures can endure against a stationary heat load of 10 MW/m2. A prediction technique, which consists of three analytical steps, is developed to estimate deformation of the divertor plate and stress in the cooling tube. A maximum stress of 350 MPa is obtained for the CFC-Cu divertor plate. Displacement of the divertor plate reduces to ±2 mm with supporting structures.