A ceiling installation type air conditioner comprising: a blower chamber including an air inlet ; a heat exchange chamber including an air outlet ; a partition plate separating the blower chamber and the heat exchange chamber from each other; a blower accommodated in the blower chamber ; and a heat exchanger accommodated in the heat exchange chamber , wherein the blower chamber is spatially connected with the heat exchange chamber via the blower ; wherein the heat exchanger includes a first heat exchange section , a second heat exchange section , and a third heat exchange section ; wherein each of the first heat exchange section , the second heat exchange section , and the third heat exchange section includes a plurality of plate-shaped fins and a plurality of heat transfer tubes ; and wherein the first heat exchange section , the second heat exchange section , and the third heat exchange section are disposed in a convex shape as a whole toward the air outlet , wherein the first heat exchange section is inclined in such a manner that an upper end portion of the first heat exchange section is positioned on a windward side of a lower end portion of the first heat exchange section , wherein the second heat exchange section is positioned at the upper portion of the heat exchange chamber and is disposed such that a front end portion of the second heat exchange section and an upper end portion of the first heat exchange section are continuous, wherein a front end portion of the third heat exchange section protrudes more towards the air outlet than the lower end of the first heat exchange section , wherein a shape of the plurality of plate-shaped fins of the first heat exchange section is line-symmetrical with a shape of the plurality of plate-shaped fins of the third heat exchange section , and in the second heat exchange section , the length dimension of a long side of each of the fins is shorter than that of the other heat exchange sections. a blower chamber including an air inlet ; a heat exchange chamber including an air outlet ; a partition plate separating the blower chamber and the heat exchange chamber from each other; a blower accommodated in the blower chamber ; and a heat exchanger accommodated in the heat exchange chamber , wherein the blower chamber is spatially connected with the heat exchange chamber via the blower ; wherein the heat exchanger includes a first heat exchange section , a second heat exchange section , and a third heat exchange section ; wherein each of the first heat exchange section , the second heat exchange section , and the third heat exchange section includes a plurality of plate-shaped fins and a plurality of heat transfer tubes ; and wherein the first heat exchange section , the second heat exchange section , and the third heat exchange section are disposed in a convex shape as a whole toward the air outlet , wherein the first heat exchange section is inclined in such a manner that an upper end portion of the first heat exchange section is positioned on a windward side of a lower end portion of the first heat exchange section , wherein the second heat exchange section is positioned at the upper portion of the heat exchange chamber and is disposed such that a front end portion of the second heat exchange section and an upper end portion of the first heat exchange section are continuous, wherein a front end portion of the third heat exchange section protrudes more towards the air outlet than the lower end of the first heat exchange section , wherein a shape of the plurality of plate-shaped fins of the first heat exchange section is line-symmetrical with a shape of the plurality of plate-shaped fins of the third heat exchange section , and in the second heat exchange section , the length dimension of a long side of each of the fins is shorter than that of the other heat exchange sections. <EOS>