A connection device including a plurality of substrates which are arranged overlapping with one another at predetermined intervals and have electrodes provided on respective opposing surfaces thereof, a connection member which has a main body section that is fixed to any one of the plurality of substrates, and a plurality of contact sections that are provided on the main body section and arranged among the plurality of substrates so as to respectively come in contact with the electrodes, and a fixing member which fixes the plurality of substrates and the main body section of the connection member to each other.