To provide a breath blowing-in port, easily treatable by anyone with a simple structure, and capable of blowing breath into an airbag in a short time, when blowing the breath into the airbag.

The breath blowing-in port for the airbag is provided so that an elliptic slipping-out preventive part 7 is installed in the breath blowing-in port, and when blowing the breath into an airbag 1, a slit part of a cylinder part of forming a circumferential slit, opens by biting the breath blowing-in port by front teeth, thereby making it easy to blowing the breath into the airbag inside After filling the airbag inside with air, the cylinder part of forming a semi-circumferential slit is brought into close contact with a breath blowing-in cylinder by pressure of the inside air of the airbag, and can prevent leakage of the air from the airbag.