Electrically heated catalyst

An electrically heated catalyst comprising:

• a heating element that heats by electrical conduction,
• a case that houses said heating element;
• an inner pipe located between said heating element and said case that provides electrical insulation;
• an inner mat, disposed in a compressed condition between said heating element and said inner pipe, that provides electrical insulation and supports said heating element, and said inner mat is shorter in a direction of a flow of exhaust gasses than said inner pipe;
• an outer mat, disposed in a compressed condition between said inner pipe and said case, that provides electrical insulation and supports said inner pipe, and said outer mat is shorter in the direction of the flow of exhaust gasses than said inner pipe;
• and
• an electrode that is in contact with said heating element, wherein
• a load per unit area acting on said inner pipe at a contact surface between said inner pipe and said outer mat is larger than a load per unit area acting on said heating element at a contact surface between said inner mat and said heating element, and
• said outer mat is shorter in the direction of the flow of exhaust gasses than said inner mat, at both upstream and downstream of the electrode in the direction of the flow of exhaust gasses.