The construction of the tabletop synchrotron MIRRORCLE‐6X is completed. The electron beam current extracted from the 6‐MeV Microtron injector is reached 100 mA with 500 ns pulse duration and 400 Hz repetition rate. The measured main magnetic field distribution of the synchrotron showed good agreement with calculation. We found that the 6‐MeV electron beam can be injected from the designed injection port to the synchrotron with 20 mm⋅mrad acceptance according to the computer simulation using measured magnetic fields. © 2004 American Institute of Physics