To provide an electric double-layered capacitor with high productivity in which external appearance deterioration due to cracks of an insulating case is not generated and the number of components is small.

A capacitor element 9 is accommodated in a part between a metal case 8 and the insulating case 7 which is engaged with the metal case 8. A first electrode surface of the element 9 is brought into contact with the metal case, with which a first lead terminal 5 is brought into contact. A second lead terminal 6 is brought into contact with a second electrode surface of the element 9. The insulating case prevents a contact between the first lead terminal and the second lead terminal and a contact between the metal case and the second electrode surface. A notched part 12 is formed in at least one portion of the insulating case, thereby controlling the progress of cracks of the insulating case.