An electrically heated catalyst device includes a catalyst support supporting a catalyst, a surface electrode disposed on an outer surface of the catalyst support and extending in an axis direction of the catalyst support, a wiring line member including a root section extending in the axis direction of the catalyst support and comb teeth-like wiring lines extending from the root section in a circumferential direction of the catalyst support and fixed to the surface electrode, an outer cylinder covering an outer surface of the catalyst support, and a holding member holding the catalyst support and packed between the catalyst support and the outer cylinder, in which the catalyst support is heated by feeding a current through the surface electrode and the wiring line member. At least a plurality of through-holes or a plurality of protrusions are formed in the root section covered by the holding member.