PROBLEM TO BE SOLVED: To provide an air supply device and an oxygen concentrator which can cool compressors and a cooking pipe while suppressing increases in device size, power consumption, and noise.SOLUTION: An oxygen concentrator 100 includes: compressors 110 for generating compressed air from raw material air a cooling pipe 121 for supplying the compressed air to sieve beds 210, 211 after cooling the compressed air by radiating the heat of the concentrated air obtained by the compressors 110 and fans 132a, 132b for cooling the cooling pipe 121 by intake air and cooling the compressors 110 by exhaust air.