An energy harvester device for an autonomous intracorporeal leadless capsule comprises a surface formed on the outside of the body of the capsule that is deformable under the effect of pressure variations in the environment surrounding the capsule. A first capacitor electrode coupling to the deformable surface with the interposition of a damping element forming high-pass filter with respect to pressure variations in the surrounding medium, and a second capacitor electrode mounting on a support connected to the body. The movement of the deformable surface produces a modification of surfaces in vis-à-vis of the two electrodes and/or of the dielectric gap which separates them, with a variation of the capacity of said capacitor. The capacitor is preloaded when its capacity is maximum, and unloaded by transferring energy into storage circuit when this capacity decreases from a reduction in surfaces in vis-à-vis and/or of an increase of the dielectric gap.
