To improve the operability in an air inlet mode selector operation means, in the air inlet mode selector device of a vehicular air conditioner in such a type as switching both inside and outside air flows by operating the air inlet mode selector operation means attached to an air conditioner control panel in a cabin.

This air inlet mode selector device A of a vehicular air conditioner is provided with an outer arm 62 formed with a cam groove 621, a turning piece 63 turning after being connected to an air inlet mode selector lever 61, and a door 3 stuck with two packing materials 4 and 5 by a linking mechanism 6 consisting of a torsion coil spring 64 whose one end is engaged with a tip of the outer arm 6, and other end is supported by a side plate 22, free of rocking motion in an air inlet door assembly.