The solid phases of ordinary methane were studied under pressure at low temperatures by the volume discontinuity method. The phase diagram of the solid is presented. A new phase was observed, and the ``missing'' phase (by analogy to CD4 and CD3D) evidently appears only under pressure at liquid helium temperatures. Observations indicate another phase at high pressures in the low‐temperature region. Indications of correlations among the phase diagrams of CH4, CH3D, and CD4 are shown.