To provide a flow channel blockage degree inspection apparatus which is simple in structure, is inexpensive, is highly responsive, and does not decrease detection accuracy by a thermal influence.

The hole blockage inspection apparatus detects the blockage of a communicating flow channel on the basis of a wind velocity when pulse air blown into the communicating channel of an object under inspection flows out of an external open port H. A through flow channel 13 having an air inlet 11 to which air blown out of the external open port of the object under inspection is introduced and an air outlet 12 is formed. A flexible plate 14 which is displaced in accordance with wind velocity is placed on the exit of the outlet 12 with a gap which does not hinder the air flow provided. The wind velocity passing through the outlet 12 is detected on the basis of the displacement of the flexible plate 14, thereby providing favorable responsiveness and reducing a decrease in the accuracy of detecting a blockage degree with less influence by heat.