We are developing a new 5x5 focal plane array receiver for the NRO 45m telescope based on the successful performance of the 2x2 focal plane array that we have been using since 1992. The main objective of this new receiver is the increase in the speed of mapping observations (25 times that of a single hone receiver) due to the large number of beams and the high sensitivity of its SIS junctions. This receiver uses fixed tuned SIS mixers and can be operated in the frequency range of 84GHz to 116GHz. It is expected that with the use of this receiver large area mapping observations (such as, nearby galaxies or nearly GMC).