A drum brake apparatus, comprising: a pair of brake shoes (27, 29) disposed opposed to an inner peripheral surface of a brake drum and elastically supported movably on a backing plate; a wheel cylinder interposed between a one-side adjoining ends of the paired brake shoes (27, 29) for expanding the paired brake shoes (27, 29) respectively; an anchor portion fixed to the backing plate and contactable by the other-side adjoining ends of the paired brake shoes (27, 29); an adjuster interposed between the one-side adjoining ends of the paired brake shoes existing near the wheel cylinder for adjusting a shoe clearance; an expansion mechanism arranged in series with the adjuster and, on receiving an operation force, for expanding the paired brake shoes respectively; a switch lever mechanism rotatably mounted on one of the brake shoes and rotatable by an action force of a given or higher value from the expansion mechanism; and a switch strut interposed between the anchor-portion side adjoining ends of the paired brake shoes (27, 29) and, following the rotation of the switch lever mechanism, for expanding the anchor-portion side adjoining ends of the paired brake shoes (27, 29), wherein the switch lever mechanism includes a first switch lever rotatably supported on one of the brake shoes by a first fulcrum pin for serving as an input side, and a second switch lever rotatably supported on the one of the brake shoes by a second fulcrum pin for serving as an output side rotatable following the first switch lever; and the first switch lever and the second switch lever are contacted at a slide contact point characterized in that the first switch lever receives an action force from the expansion mechanism between a slide contact point of the first switch lever and the second switch lever and the first fulcrum pin. a pair of brake shoes (27, 29) disposed opposed to an inner peripheral surface of a brake drum and elastically supported movably on a backing plate; a wheel cylinder interposed between a one-side adjoining ends of the paired brake shoes (27, 29) for expanding the paired brake shoes (27, 29) respectively; an anchor portion fixed to the backing plate and contactable by the other-side adjoining ends of the paired brake shoes (27, 29); an adjuster interposed between the one-side adjoining ends of the paired brake shoes existing near the wheel cylinder for adjusting a shoe clearance; an expansion mechanism arranged in series with the adjuster and, on receiving an operation force, for expanding the paired brake shoes respectively; a switch lever mechanism rotatably mounted on one of the brake shoes and rotatable by an action force of a given or higher value from the expansion mechanism; and a switch strut interposed between the anchor-portion side adjoining ends of the paired brake shoes (27, 29) and, following the rotation of the switch lever mechanism, for expanding the anchor-portion side adjoining ends of the paired brake shoes (27, 29), wherein the switch lever mechanism includes a first switch lever rotatably supported on one of the brake shoes by a first fulcrum pin for serving as an input side, and a second switch lever rotatably supported on the one of the brake shoes by a second fulcrum pin for serving as an output side rotatable following the first switch lever; and the first switch lever and the second switch lever are contacted at a slide contact point characterized in that the first switch lever receives an action force from the expansion mechanism between a slide contact point of the first switch lever and the second switch lever and the first fulcrum pin.