Resume. Multiwire proportional chamber is a conventional technique to study radiation in general, and cosmic rays in particular. To study cosmic rays, it was planned, designed, constructed, characterized, and tested a four channel mini wire chamber, based on two 3 cm X 3 cm X 0.6 cm Aluminum frames, two 3 cm X 3 cm X 0.6 cm plastic frames, two 3 cm X 3 cm X 0.3 cm Aluminum frames, two electronic planes each with two Tungsten Gold plated 1 mil diameter wires, parallel and 1 cm apart each other at 30 g stretched -each plane was 90o rotated each other in the final assemble- and two Aluminum foil window to define the gas volume; it was operated with Argon 90%-CH4 10% gas mixture at 1 atmosphere and ambient temperature (20oC in the average). It is presented technical details, results on characterization, and preliminary results on cosmic rays detection.

Cosmic ray and astroparticle physics