Measurements were made of the air pressure beneath, along one side of and within vibrating particle beds. Experiments were conducted using two different size ranges of glass beads (99 and 227 mum in mean diameter) with two bed heights, 100 and 120 mm. The lateral air pressure distribution was found to be fairly uniform near the bottom of the bed for all the particle beds tested. However, in beds of small particles, the difference in the magnitude between the peak air pressure on a vessel wall and those at other lateral positions (at a given depth) increased with decreasing bed depth, and passed through a maximum at a certain depth in the upper half region of the bed. In beds of large particles the lateral air pressure distribution was fairly uniform throughout the bed, although humps appeared in the pressure profile due to the collision between large particles and a small sensor immersed within the bed. The hump, however, did not prevent us from discerning the relative magnitude of the peak air pressures at a given bed depth.