  We report on the electrostatic trapping of neutral SrF molecules. The
molecules are captured from a cryogenic buffer-gas beam source into the moving
traps of a 4.5 m long traveling-wave Stark decelerator. The SrF molecules in
$X^2\Sigma^+(v=0, N=1)$ state are brought to rest as the velocity of the moving
traps is gradually reduced from 190 m/s to zero. The molecules are held for up
to 50 ms in multiple electric traps of the decelerator. The trapped packets
have a volume (FWHM) of 1 mm$^{3}$ and a velocity spread of 5(1) m/s which
corresponds to a temperature of $60(20)$ mK. Our result demonstrates a factor 3
increase in the molecular mass that has been Stark-decelerated and trapped.
Heavy molecules (mass$>$100 amu) offer a highly increased sensitivity to probe
physics beyond the Standard Model. This work significantly extends the species
of neutral molecules of which slow beams can be created for collision studies,
precision measurement and trapping experiments.
