This invention provides a normally open solenoid valve without using welding fluid for soldering and air conditioner using this solenoid valve, comprising a small diameter part (12a) having allocated plunger compartment (11) and being composed of stainless steel made stepped tubes, a large diameter part (13) having allocated valve chambers (13), and plunger piston tube on stepped part (12c) as the main body. Stainless steel made spring supporting and wrapping assembly is located and fixed by means of fitting with stepped surface inside tube of the stepped part via soldering process in atmosphere oven without using welding fluid, and used for fixing part of plunger supporting spring (16) and wrapped around fore end of valve core (21) on valve opening position. The spring supporting and wrapping assembly is disposed with a holding component (22c2) for holding ring-shaped solder material on the soldering part until soldering process without welding fluid (R).