A heat-insulating sheet includes a heat storage sheet, a first insulating sheet, and a thermally conductive sheet. The heat storage sheet contains a first resin and a plurality of microcapsules containing latent heat storage material and mixed in the form of aggregates with each other. The first insulating sheet has a first face bonded to the heat storage sheet and a second face opposite to the first face. The thermally conductive sheet is bonded to the second face of the first insulating sheet. The content of the microcapsules in the heat storage sheet is falls within a range from 40 wt % to 90 wt %, inclusive. The heat storage sheet includes a layer free from the microcapsules at a portion in contact with the first insulating sheet.