A device for detecting aldehydes or ketones, comprising a rotary platform of a disk shape; and a microfluidic structure disposed on the rotary platform, wherein the microfluidic structure includes: a sample storage unit comprising a filling of 2,4-dinitrophenylhydrazine coated silica (2, 4-DNPH-coated silica) in the form of beads and into which a fluid sample containing aldehydes or ketones is injected to derivatize the aldehydes or the ketones with the filling; an eluent storage unit into which an eluent is injected; a separation unit having a TLC plate that receives the sample and the eluent from the sample storage unit and the eluent storage unit, and separates and deploys the aldehydes or the ketones of the sample with the eluent; a first microfluidic channel (siphon channel) that is a passage through which the sample moves to the separation unit, and connects the sample storage unit and the separation unit; a second microfluidic channel that is a passage through which the eluent moves to the separation unit, and connects the eluent storage unit and the separation unit; and an absorption pad that receives the eluent from the eluent storage unit and discharges it to the TLC plate, whereby the microfluidic structure further includes a first vent hole and a second vent hole through which an external gas is injected into the separation unit or a gas inside the separation unit is discharged to an exterior, a first air circulation channel which is a passage through which a gas moves between the first vent hole and the separation unit, and a second air circulation channel which is a passage through which a gas moves between the second vent hole and the separation unit, and whereby the first air circulation channel is connected to one end of the separation unit, and the second air circulation channel is connected to the other end of the separation unit. a rotary platform of a disk shape; and a microfluidic structure disposed on the rotary platform, wherein the microfluidic structure includes: a sample storage unit comprising a filling of 2,4-dinitrophenylhydrazine coated silica (2, 4-DNPH-coated silica) in the form of beads and into which a fluid sample containing aldehydes or ketones is injected to derivatize the aldehydes or the ketones with the filling; an eluent storage unit into which an eluent is injected; a separation unit having a TLC plate that receives the sample and the eluent from the sample storage unit and the eluent storage unit, and separates and deploys the aldehydes or the ketones of the sample with the eluent; a first microfluidic channel (siphon channel) that is a passage through which the sample moves to the separation unit, and connects the sample storage unit and the separation unit; a second microfluidic channel that is a passage through which the eluent moves to the separation unit, and connects the eluent storage unit and the separation unit; and an absorption pad that receives the eluent from the eluent storage unit and discharges it to the TLC plate, whereby the microfluidic structure further includes a first vent hole and a second vent hole through which an external gas is injected into the separation unit or a gas inside the separation unit is discharged to an exterior, a first air circulation channel which is a passage through which a gas moves between the first vent hole and the separation unit, and a second air circulation channel which is a passage through which a gas moves between the second vent hole and the separation unit, and whereby the first air circulation channel is connected to one end of the separation unit, and the second air circulation channel is connected to the other end of the separation unit. a sample storage unit comprising a filling of 2,4-dinitrophenylhydrazine coated silica (2, 4-DNPH-coated silica) in the form of beads and into which a fluid sample containing aldehydes or ketones is injected to derivatize the aldehydes or the ketones with the filling; an eluent storage unit into which an eluent is injected; a separation unit having a TLC plate that receives the sample and the eluent from the sample storage unit and the eluent storage unit, and separates and deploys the aldehydes or the ketones of the sample with the eluent; a first microfluidic channel (siphon channel) that is a passage through which the sample moves to the separation unit, and connects the sample storage unit and the separation unit; a second microfluidic channel that is a passage through which the eluent moves to the separation unit, and connects the eluent storage unit and the separation unit; and an absorption pad that receives the eluent from the eluent storage unit and discharges it to the TLC plate, whereby the microfluidic structure further includes a first vent hole and a second vent hole through which an external gas is injected into the separation unit or a gas inside the separation unit is discharged to an exterior, a first air circulation channel which is a passage through which a gas moves between the first vent hole and the separation unit, and a second air circulation channel which is a passage through which a gas moves between the second vent hole and the separation unit, and whereby the first air circulation channel is connected to one end of the separation unit, and the second air circulation channel is connected to the other end of the separation unit.