To provide an envelope in a simple structure for home delivery or mailing, can be extremely simply opened, and can be provided at a low cost.

A seal label 2 is provided at the upper part of an envelope surface 11 of an envelope body 1, and a strip 4 and a release paper 5 with the same member are continuously stuck from the side of the envelope surface 11 on this back face through an adhesive layer 3. The whole boundary of the strip 4 and the release paper 5 is divided with a slit c, and an initial notch 7 for raising the end of the strip 4 existing on the back face of the seal label 2 is formed at least on one end in the longitudinal direction of the strip 4 on the surface of the seal label 2 at both positions of the width of the strip 4. The strip 4 has a strength enough to tear off the seal label 2 by raising the strip 4. The seal label 2 is composed of a different member from the envelope surface 11, and on the lower part of the seal label 2, a sticking part is extended with the same member, and this is stuck on the upper part of the envelope surface 11 through the adhesive layer 3.