A thermal type flow rate measuring apparatus, comprising: a heat-generating element disposable in the flow of a fluid that generates heat when electric current flows therethrough; first and second temperature-detecting means (3, 4, 7, 8) disposed on both sides of the heat-generating element along the flow of the fluid; a heat-generating element connecting terminal (31. 32) electrically connected to the heat-generating element; first and second temperature-detecting means connecting terminals (25-28, 33-36) electrically connected to the first and second temperature-detecting means (3, 4, 7, 8); a heat-generating element wiring portion (18, 24) electrically connecting the heat-generating element and the heat-generating element connecting terminal (31, 32); and first and second temperature-detecting means wiring portions (10-13, 19-22) electrically connecting the first and second temperature-detecting means (3, 4, 7, 8) and the first and second temperature-detecting means connecting terminals (25-28, 33-36), respectively, wherein the apparatus further comprises: a wiring pattern (14, 23) disposed between the heat-generating element wiring portion (18, 24) and the first and second temperature-detecting means wiring portions (10-13, 19-22), and wherein the wiring pattern (14, 23) is held at a constant potential, the apparatus characterized by further comprising: heat-generating element temperature-detecting means disposed near the heat-generating element for detecting the temperature of the heat-generating element; a heat-generating element temperature-detecting means connecting terminal (29, 30) which is electrically connected with the heat-generating element temperature-detecting means; and a heat-generating element temperature-detecting means wiring portion (15, 16) electrically connecting the heat-generating element temperature-detecting means with the heat-generating element temperature-detecting means connecting terminal (29, 30); and a wiring pattern disposed between the heat-generating element wiring portion (18, 24) and the heat-generating element temperature-detecting means wiring portion (15, 16), wherein the wiring pattern is held at a constant potential. a heat-generating element disposable in the flow of a fluid that generates heat when electric current flows therethrough; first and second temperature-detecting means (3, 4, 7, 8) disposed on both sides of the heat-generating element along the flow of the fluid; a heat-generating element connecting terminal (31. 32) electrically connected to the heat-generating element; first and second temperature-detecting means connecting terminals (25-28, 33-36) electrically connected to the first and second temperature-detecting means (3, 4, 7, 8); a heat-generating element wiring portion (18, 24) electrically connecting the heat-generating element and the heat-generating element connecting terminal (31, 32); and first and second temperature-detecting means wiring portions (10-13, 19-22) electrically connecting the first and second temperature-detecting means (3, 4, 7, 8) and the first and second temperature-detecting means connecting terminals (25-28, 33-36), respectively, wherein the apparatus further comprises: a wiring pattern (14, 23) disposed between the heat-generating element wiring portion (18, 24) and the first and second temperature-detecting means wiring portions (10-13, 19-22), and wherein the wiring pattern (14, 23) is held at a constant potential, the apparatus characterized by further comprising: a wiring pattern (14, 23) disposed between the heat-generating element wiring portion (18, 24) and the first and second temperature-detecting means wiring portions (10-13, 19-22), and wherein the wiring pattern (14, 23) is held at a constant potential, the apparatus characterized by further comprising: heat-generating element temperature-detecting means disposed near the heat-generating element for detecting the temperature of the heat-generating element; a heat-generating element temperature-detecting means connecting terminal (29, 30) which is electrically connected with the heat-generating element temperature-detecting means; and a heat-generating element temperature-detecting means wiring portion (15, 16) electrically connecting the heat-generating element temperature-detecting means with the heat-generating element temperature-detecting means connecting terminal (29, 30); and a wiring pattern disposed between the heat-generating element wiring portion (18, 24) and the heat-generating element temperature-detecting means wiring portion (15, 16), wherein the wiring pattern is held at a constant potential.