The development and testing of a gas-pressurized μSR setup for the RIKEN-RAL Muon Facility is reported. In collaboration with the high-pressure group of the ISIS Facility at the Rutherford Appleton Laboratory, a gas-pressurized setup for a pulsed muon beam at the RIKEN-RAL Muon Facility has been constructed in 2008. The sample is pressurized by helium gas and the designed maximum pressure is 6.4kbar. The high-pressure cell can be cooled down to 2K using an existing cryostat. Tests were made injecting the double-pulsed muon beam into a high-purity sample of Sn powder, which confirmed that the maximum pressure achieved at 2K was close to the designed pressure.