An air conditioner characterized by comprising: a blower device comprising: a centrifugal fan; and a first casing that houses the centrifugal fan, the first casing having an intake opening provided at a location in a direction of a rotation axis of the centrifugal fan at which the intake opening faces the centrifugal fan and having a discharge opening provided at a location in a circumferential wall of the first casing at which the discharge opening faces the centrifugal fan in a direction perpendicular to the rotation axis of the centrifugal fan; and a heat-exchange device comprising: a heat-exchange element that is pillar-shaped; and a second casing that is cuboid-shaped and houses the heat-exchange element, the second casing having an introduction opening for introducing into an interior of the second casing air discharged, via the discharge opening, by the centrifugal fan and having an ejection opening for ejecting, to outside of the second casing, air introduced into the interior of the second casing and heat-exchanged by the heat-exchange element, characterized in that the heat-exchange device comprises a number of heater elements arranged such that the lengthwise direction of each heater element is parallel with the rotation axis of the centrifugal fan; a portion of each heater element is arranged beyond region A1 being the region into which a majority of the air discharged via the discharge opening of the first casing flows, when the blower device is used; said region A1 includes the edges of the discharge opening of the first casing in the rotation axis direction of the centrifugal fan and corresponds to an area defined between two virtual planes PL1 and PL2 that are perpendicular to the rotation axis J1 of the centrifugal fan; wherein the second casing is configured such that a flow of air introduced into the interior of the second casing via the introduction opening spreads out in a lengthwise direction of the heat-exchange element coming in contact with the entirety of each heater element. a blower device comprising: a centrifugal fan; and a first casing that houses the centrifugal fan, the first casing having an intake opening provided at a location in a direction of a rotation axis of the centrifugal fan at which the intake opening faces the centrifugal fan and having a discharge opening provided at a location in a circumferential wall of the first casing at which the discharge opening faces the centrifugal fan in a direction perpendicular to the rotation axis of the centrifugal fan; and a centrifugal fan; and a first casing that houses the centrifugal fan, the first casing having an intake opening provided at a location in a direction of a rotation axis of the centrifugal fan at which the intake opening faces the centrifugal fan and having a discharge opening provided at a location in a circumferential wall of the first casing at which the discharge opening faces the centrifugal fan in a direction perpendicular to the rotation axis of the centrifugal fan; and a heat-exchange device comprising: a heat-exchange element that is pillar-shaped; and a second casing that is cuboid-shaped and houses the heat-exchange element, the second casing having an introduction opening for introducing into an interior of the second casing air discharged, via the discharge opening, by the centrifugal fan and having an ejection opening for ejecting, to outside of the second casing, air introduced into the interior of the second casing and heat-exchanged by the heat-exchange element, a heat-exchange element that is pillar-shaped; and a second casing that is cuboid-shaped and houses the heat-exchange element, the second casing having an introduction opening for introducing into an interior of the second casing air discharged, via the discharge opening, by the centrifugal fan and having an ejection opening for ejecting, to outside of the second casing, air introduced into the interior of the second casing and heat-exchanged by the heat-exchange element, characterized in that the heat-exchange device comprises a number of heater elements arranged such that the lengthwise direction of each heater element is parallel with the rotation axis of the centrifugal fan; a portion of each heater element is arranged beyond region A1 being the region into which a majority of the air discharged via the discharge opening of the first casing flows, when the blower device is used; said region A1 includes the edges of the discharge opening of the first casing in the rotation axis direction of the centrifugal fan and corresponds to an area defined between two virtual planes PL1 and PL2 that are perpendicular to the rotation axis J1 of the centrifugal fan;