Emblem body includes emblem main body section and pin projecting to emblem main body section and inserted through opening section. Pin has shaft section continuous with emblem main body section, enlargement section formed to be enlarged on the distal end side of shaft section, planar section formed in a planar shape along a direction intersecting with the protrusion direction of pin in enlargement section, and linear section linearly formed at a position different from planar section along a direction intersecting with the protrusion direction of pin in enlargement section. Back plate is provided with elastic piece section against which planar section and linear section abut from the direction opposite to the protrusion direction of pin at least during airbag inflation deployment.