The ALPS II experiment, Any Light Particle Search II at DESY in Hamburg, will look for light (m<10−4eV) new fundamental bosons (e.g., axion-like particles, hidden photons and other WISPs) in the next years by the mean of a light-shining-through-the-wall setup. The ALPS II photosensor is a Transition-Edge Sensor (TES) optimized for λ=1064 nm photons. The detector is routinely operated at 80 mK, allowing single infrared photon detections as well as non-dispersive spectroscopy with very low background rates. The demonstrated quantum efficiency for such TES is up to 95% at λ=1064,nm as shown in [1]. For 1064 nm photons, the measured background rate is <10−2sec−1 and the intrinsic dark count rate in a dark environment was found to be of 1.0⋅10−4sec−1 [2]. Latest characterization results are discussed.