A solder alloy is provided which suppresses the change in a solder paste over time, decreases the temperature difference between the liquidus-line temperature and the solidus temperature, and exhibits a high reliability. The solder alloy has an alloy constitution composed of: 10 ppm by mass or more and less than 25 ppm by mass of As; at least one selected from the group consisting of 0 ppm by mass to 10000 ppm by mass of Bi and 0 ppm by mass to 5100 ppm by mass of Pb; more than 0 ppm by mass and no more than 3000 ppm by mass of Sb; and a remaining amount of Sn; and satisfies both the formula (1) and the formula (2). 300≤3As+Sb+Bi+Pb  (1) 0.1≤{(3As+Sb)/(Bi+Pb)}×100≤200  (2) In the formula (1) and the formula (2), As, Sb, Bi, and Pb each represents an amount thereof (ppm by mass) in the alloy constitution.