A portable handheld sampling device for collecting aerosol particles in a stream of exhaled breath provided with an inlet and an outlet, wherein the sampling device further comprises a housing and a collecting device holder removably arranged at least partially inside the housing, wherein the housing and the collecting device holder are arranged to guide the stream of exhaled breath through the device from the inlet to the outlet, wherein said collecting device holder comprises at least two cylindrical conduits arranged in parallel, each defining a flow path in fluid connection with the inlet, wherein a cylindrical collecting device is arranged in each conduit, the collecting device being adapted to collect the aerosol particles in the exhaled breath. A method for collecting aerosol particles in exhaled breath of a user using a portable handheld sampling device by means of a reopening breathing maneuver.