There is provided a connection structure between a Si electrode (Si member) and an Al wire (Al member). Between the Si electrode and the Al wire, a first part and second parts are present in interposed relation. Each of the first and second parts is in contact with the Si electrode and with the Al wire. In the first part, a Si oxide layer and an Al oxide layer are present. The Si oxide layer is in contact with the Si electrode. The Al oxide layer is interposed between the Si oxide layer and the Al wire. In some of the second parts, Al is present. In the others of the second parts, a Si portion and an Al portion are present.