A wiring forming method comprising: forming wiring on multiple substrates of different materials (34, 60a, 60b) by baking a metal-containing liquid that is a liquid containing metal particles, wherein the forming includes applying the metal-containing liquid straddling multiple different types of substrate materials, and baking the metal-containing liquid applied during the applying with a laser, wherein the laser emission amount per unit of area is changed based on the substrate material for each of the multiple substrates (34, 60a, 60b) when baking the metal-containing liquid, wherein the applying includes applying the metal-containing liquid straddling a first substrate and a second substrate (60a, 60b) that has at least one of a higher thermal conductivity than the thermal conductivity of the first substrate, a higher thermal capacity than the thermal capacity of the first substrate, or a larger volume than the volume of the first substrate, characterized in that the baking includes a first baking process of baking the metal-containing liquid applied on the first substrate by applying the laser corresponding to a first set emission amount, which is a laser emission amount per unit of area set according to the first substrate, and a second baking process of, after the first baking processing is complete, baking the metal-containing liquid applied on the second substrate (60a, 60b) by applying the laser corresponding to an emission amount that is equal to or less than a second set emission amount, which is a laser emission amount per unit of area set according to the second substrate (60a, 60b), and greater than the first set emission amount. forming wiring on multiple substrates of different materials (34, 60a, 60b) by baking a metal-containing liquid that is a liquid containing metal particles, wherein the forming includes applying the metal-containing liquid straddling multiple different types of substrate materials, and baking the metal-containing liquid applied during the applying with a laser, wherein the laser emission amount per unit of area is changed based on the substrate material for each of the multiple substrates (34, 60a, 60b) when baking the metal-containing liquid, wherein the applying includes applying the metal-containing liquid straddling a first substrate and a second substrate (60a, 60b) that has at least one of a higher thermal conductivity than the thermal conductivity of the first substrate, a higher thermal capacity than the thermal capacity of the first substrate, or a larger volume than the volume of the first substrate, characterized in that the baking includes a first baking process of baking the metal-containing liquid applied on the first substrate by applying the laser corresponding to a first set emission amount, which is a laser emission amount per unit of area set according to the first substrate, and a second baking process of, after the first baking processing is complete, baking the metal-containing liquid applied on the second substrate (60a, 60b) by applying the laser corresponding to an emission amount that is equal to or less than a second set emission amount, which is a laser emission amount per unit of area set according to the second substrate (60a, 60b), and greater than the first set emission amount.