A magnetic beam analyzer system and a product-particle spectrometer of a broad-range type for a 55-MeV proton beam from the INS Tokyo synchrocyclotron are described. The beam analyzer system consists of a beam analyzer magnet and a beam cleaning magnet. A well focused and cleaned beam is obtained at the target position. The beam intensity is about 45 nA when the energy spread of the analyzed beam is 0.1%. The product-particle spectrometer is composed of a uniform-field sectorial magnet and a preceding quadrupole-magnet doublet. The spectrometer can analyze and detect simultaneously particles over an energy range from E max to 0.67 E max. A multicounter system of an array of 200 proportional counters followed by a large plastic scintillation counter system is arranged at the focal plane of the spectrometer. The 200 proportional counters serve as position detectors, and compose counter telescopes with the scintillation counters. A momentum spectrum of analyzed particles is stored and displayed by the use of the core memory of a 1024 channel pulse height analyzer. An over-all energy resolution 0.14% and a solid angle 2 × 10 −3 sr are obtained. The design, construction, testing, and operation of the magnetic analyzer system are described. Results of various calibrations, i.e. plots of dispersion, resolution, solid angle, energy measurements, etc. are given.