We have studied the atmospheric pressure plasma generated using a quartz tube, helium gas, and foil electrode by applying AC high voltage. The plasma plume is released into the atmosphere from inside the quartz tube. The helium plasma temperature is investigated using a line pair method. The excitation temperature of the electrons in the helium plasma is estimated at about 700K along the plasma plume (column). The excitation temperature of the electrons decreases slightly towards the tip of the plasma plume. Because the emitted light of the helium ion (He I) excitation at a wavelength of 706 nm is weak at the tip of the plasma plume, the electron excitation temperature is overestimated. In the atmosphere region near the tip of the plasma plume, collisions between helium gas and air increase. Therefore, the electron excitation temperature determined using the observed emitted light from helium ion excitation inside of the quartz tube filled with a helium gas. (C) 2016 AIP Publishing LLC.