  Near-Earth asteroid (3200) Phaethon is notable for its association to a
strong annual meteor shower, the Geminids, indicative of one or more episodes
of mass ejection in the past. The mechanism of Phaethon's past activity is not
yet understood. Here we present a Hubble Space Telescope (HST) search of
meter-sized fragments in the vicinity of Phaethon, carried out during
Phaethon's historic approach to the Earth in mid-December of 2017. Numerical
simulation conducted to guide HST's pointing also show that the dynamical
evolution of Phaethon-originated particles is quick, as ejected materials take
no longer than $\sim250$ yr to spread to the entire orbit of Phaethon. Our
search was completed down to 4-meter-class limit (assuming Phaethon-like
albedo) and was expected to detect 0.035% particles ejected by Phaethon in the
last several decades. The negative result of our search capped the total mass
loss of Phaethon over the past few dozen orbits to be $10^{12}$ kg at $3\sigma$
level, taking the best estimates of size power-law from meteor observations and
spacecraft data. Our result also implies a millimeter-sized dust flux of
$<10^{-12} \mathrm{m^{-2} s^{-1}}$ within 0.1 au of Phaethon, suggesting that
any Phaethon-bound mission is unlikely to encounter dense dust clouds.
