To suppress electricity from flowing in a case of an electric heating catalyst.
An electric heating catalyst 1 includes: a heating element 3 heated by energization; a case 5 housing the heating element 3; and a mat 4 insulating electricity by being held between the hating element 3 and the case 5 including an outer pipe 51 serving as a partition from outside, and an inner pipe 52 contained inside the outer pipe 51. An upstream side end of the inner pipe 52 is provided at the upstream side from the mat 4. A gap is provided between the outer pipe 51 and the inner pipe 52 at the upstream side end of the inner pipe 52 so that a space between the outer pipe 51 and the inner pipe 52 is opened in an exhaust path. A downstream side end of the inner pipe 52 is provided at a part contacting the mat 4. The outer pipe 51 and the inner pipe 52 are brought into contact with each other at the downstream side end so that a space between the outer pipe 51 and the inner pipe 52 is closed.
WATANABE TAKESHI
Kazunobu Sera
Akira Hirakawa
Takehiko Sekine
Katsuhiko Imahori
Fuminori Miyashita