The International Muon Collider Collaboration has proposed a multi-TeV muon collider as a powerful tool to investigate the Standard Model with unprecedented precision, after the High-Luminosity LHC era. However, muons are not stable particles and it is of extreme importance to develop technologies able to distinguish genuine hits, originating from particles created in collisions, from hits due to the background radiation induced by the beam itself. In this context, an innovative hadronic calorimeter (HCAL), based on Micro-Pattern Gaseous Detectors (MPGD) as active layers, has been proposed. MPGDs represent the ideal technology, featuring high rate capability, good spatial and time resolution, good response uniformity and, moreover, they are radiation hard and allow for high granularity readout (1$\times 1\mbox{ cm}^2$ cell size). The response of an MPGD HCAL to the incoming particles is studied in Monte Carlo simulations and presented here. The tests performed at SPS with muons of 100 GeV, for the detector characterization, and at PS with pions of few GeV, for a HCAL cell prototype study, are also shown.