Spell Cards, and their effects on the field, cannot be activated. Negate all Spell effects on the field.
Rulings
Individual Card FAQs
"Spell Canceller"'s effect is similar to "Imperial Order".
If "Last Will"'s effect is active (its 'state' is in effect) and "Spell Canceller" is Summoned, "Spell Canceller" will not negate the effect of "Last Will".
You can Special Summon "Spell Canceller" with "Premature Burial"; the effect of "Premature Burial" is negated by "Spell Canceller" so if "Premature Burial" is destroyed, "Spell Canceller" is not destroyed and remains on the field.
You can chain "Call of the Haunted" to a Spell Card, and Special Summon "Spell Canceller", to negate the effect of the Spell Card.
You can activate "Spiritualism" when "Spell Canceller" is face-up on the field because its activation and effect cannot be negated.
When "Spell Canceller" is face-up on the field, you can activate the Graveyard effect of "Dark Necrofear" (because it is a monster effect) and equip it to a monster, but the effect of "Dark Necrofear" after it is equipped will be negated because it is then an Equip Spell Card.
WIND|
Level 5|[ Machine / Effect ]
ATK 1800|
DEF 1600