Star clusters are key to understand the stellar and Galactic evolution .
ASCC 123 is a little-studied , nearby and very sparse open cluster .
We performed the first high-resolution spectroscopic study of this cluster in the framework of the SPA ( Stellar Population Astrophysics ) project with GIARPS at the TNG .
We observed 17 stars , five of which turned out to be double-lined binaries .
Three of the investigated sources were rejected as members on the basis of astrometry and lithium content .
For the remaining single stars we derived the stellar parameters , extinction , radial and projected rotational velocities , and chemical abundances for 21 species with atomic number up to 40 .
From the analysis of single main-sequence stars we found an average extinction A _ { V } \simeq 0.13 mag and a median radial velocity of about -5.6 km s ^ { -1 } .
The average metallicity we found for ASCC 123 is [ Fe/H ] \simeq + 0.14 \pm 0.04 , which is in line with that expected for its Galactocentric distance .
The chemical composition is compatible with the Galactic trends in the solar neighborhood within the errors .
From the lithium abundance and chromospheric H \alpha emission we found an age similar to that of the Pleiades , which agrees with that inferred from the Hertzsprung-Russell and color-magnitude diagrams .