To provide a pressure sensor which makes the same the sizes of thermal stresses applied on first and second pressure detection parts.

The pressure sensor S1 comprises: a case 10; first and second sensor chips 20 and 30 stored in the inside of the case 10; first and second pressure introduction holes 40 and 50 communicating with each of the first and second sensor chips 20 and 30; and a semiconductor circuit chip 60 for calculating a difference between the detection results of the first and second sensor chips 20 and 30. A plane layout of the case 10 mutually line-symmetrically arranges the first and second pressure introduction holes 40 and 50, and mutually line-symmetrically arranges the first and second sensor chips 20 and 30 by regarding a pressure partition wall as a reference.