PURPOSE: To obtain a helmet capable of preventing extraordinary noise generation in sucking ventilation caused by the running wind, in spite of the presence of a space of air chamber in between a draught through hole in a crown and a connecting hole in a liner for impact absorption.

CONSTITUTION: A sponge like flow regulating material 9 capable of adjusting an abnormal air flow in an air chamber 8, is placed directly at an inside part of a draught through hole 4, as well as in the air chamber 8 connected to a hole 5 of an impact absorption liner 2 constructed at an inside of a crown portion 1 where the draught hole 4 is also constructed.