Abstract: A method for manufacturing a connection construction having a first and a second connection members bonded therebetween with a solder layer includes the steps of: sandwiching the solder layer between the first and the second connection members; decompressing the solder layer down to a first pressure with maintaining a first temperature, which is lower than a solidus of the solder; heating the solder layer up to a second temperature with maintaining the first pressure, the second temperature being higher than a luquidus of the solder; compressing the solder layer up to a second pressure with maintaining the second temperature, the second pressure being higher than the first pressure; and hardening the solder with maintaining the second pressure.