Recent developments on new cancer treatment modalities show an improvement of the dose delivery to the tumor while sparing healthy tissues. Among those, FLASH therapy based on the use of low energy electron beams at very high dose rates is a promising technique. However, for these beams, doses-per-pulse are up to several orders of magnitude higher than those produced by conventional radiation sources. In these conditions, conventional active dosimeters as diodes or ionization chambers saturate. Consequently, such devices cannot be used to ensure the on-line dosimetry of those beams. Moreover, passive dosimeters as EBT are not very well adapted for clinical uses in routine. In this context, CEA-LIST, in the frame of ASTROLABE (fAst ScinTillatoR based device for On line FLASH BEam dosimetry) project, in collaboration with Institut Curie, is developing a dedicated point dosimeter for FLASH beams monitoring. This alternative technology is based on the coupling of a homemade fast plastic scintillator (water equivalent), tuned in response time and wavelength emission, with a PMMA waveguide and a silicon photomultiplier sensor (SiPM). Moreover, in order to estimate the Cerenkov contribution, a twin device without plastic scintillator is also produced. This talk aims to present the development steps and results obtained from these both devices. Those include fast plastic scintillator selection after their characterization in laboratory, using ¹³⁷Cs radioactive source, point dosimeters assembly phases and measurements performed under electron FLASH beams (7 MeV), in Institut Curie, in Orsay.